Unsigned group The Trisha’s blend of country, blues, bluegrass, and Americana was on display every night in Austin. In this showcase at Maggie Mae’s Gibson Room on Friday, guitarist Kelley Mickwee gets the most out of a booming 2005 Gibson J-200 normally played by guitarist Jamie Wilson, who says, “The low end in it is enormous, and for us (with no bass player) that's a big part of our sound.”